Pumping and feeding mechanism for mixing machines



June 6, 1944. E. G. BERG ET AL r 2,350,715

PUMPING AND'FEEDING MECHANISM FOR MIXING MACHINES Filed Feb. l6. 1942 2Sheets-Sheet 1 Emu G. Bane New; OyEamuu June 6, 1944. E. s. BERG EF/AL2,350,715

- PUMPING AND FEEDING MECHANISM FCR MIXING MACHINES Filed Feb. 16. 19422 Sheets-Sheet 2 gwuwvtou I Beam 6:. Buzz: New: Ooesrzuo all-WW PatentedJune 6, 1944 PUMPING AND FEEDING MECHANISM FOR MIXING MACHINES Egon G.Berg and Melvin Ovestrud, Minneapolis, Minn., asslgnors to PioneerEngineering Works, Inc., Minneapolis, Minn., a corporation of DelawareApplication February 16, 1942, Serial No. 431,048

1 Claim.

for pumping, feeding and otherwise handling the fluid materials used insuch work.

' The machine of the type herein contemplated embodies means for mixingan aggregate or base coarse material with a binder or liquid bindingmaterial either of a bituminous or aqueous variety. Such machines embodya storage tank for the binder and must include means for pumping thematerial into the tank from the source. of supply, pumping the materialinto the mixing apparatus and performing other such operations.

It is the primary object of this invention to provide a mechanism orsystem of piping, pumps and valves by means of which all commonlyemployed fluid binding agents may be handled and which will have extremeflexibility of operation and adjustment in order to meet thecontinuously varying problems and conditions encountered in roadbuilding work. Another object is to provide an assembly of this kind insimple and conveniently controlled form.

These and other more detailed and specific objects will be disclosed inthe course of the following specification, reference being had to theaccompanying drawings, in which Fig. 1 is a side elevation of a machinefor mix ing road building materials and showing my invention appliedthereto. I

Fig. 2 is a somewhat diagrammatical showing of the entire pumping andpiping system constituting the present invention.

Fig. 3 is a detail view in vertical cross section through the spraybars.

This application is a continuation in part from our copendingapplication for patent on a Mixing machine, Serial No. 357,708, filedSeptember 21, 1940, now Patent No. 2,297,867, issued October 6, 1942,and to which attention is invited for a complete disclosure of themachine as a whole. Only such parts of the machine as are necessary tothe understanding of the present invention are herein shown anddescribed.

Referring now more particularly and by reference characters to thedrawings, A represents the frame of the machine which is wheel borne byfront and rear trucks B and C and is adapted to be pulled along thehighway by a draft connection to the tongue D. A hopper E receives theaggregate or base coarse material and delivers it in desired quantityand at any desired rate to the pug mill or mixer F, wherein it isthoroughly agitated and mixed with the binding liquid and finallydischarged at the chute G. A large storage tank T is built into theframe A to carry a quantity of the binding material.

The present invention lies in the means for supplying the binding liquidto the tank and properly pumping and metering the liquid as it issprayed on the material in the pug mill F.

The tank '1 is filled from a relay truck tank, not shown, or othersupply by connection therewith of a flexible hose 5 which may beattached at one end to either coupling 6 or I' disposed at the ends of areceiving pipe 8 extending transversely at the rear lower portion of theframe A. The end of the hose 5 has a conventional coupling 9 for makingconnection to the truck and the couplings 6 and '1 permit connection tothe mixing machine at whichever side is most convenient. When not in usethe hose 5 is supported in brackets II] as clearly shown in Fig. 1.

Afiller pipe I I is connected to one end of pipe 8 and runs forwardlytherefrom and around to the front of the machine where it is connectedto the intake side of a transfer pump I 4. A strainer I5 is placed inthe pipe I I to protect the transfer pump from foreign matter and theoutlet side of the pump is connected by pipe I6 to the tank T. Obviouslythe transfer pump I 4 thus connected will set up a suction through hose5 and will pump the binding liquid into the tank.

A volumetric metering type of pump I! is used for feeding the bindingliquid from the tank '1' to the spraying equipment and to secureconstant suction the pump is arranged beneath the tank as best seen inFig. 1. A suction line or pipe I8 connects the feeder pump I! to anoutlet connection I9 to the tank and a strainer 20 is located in thisline to protect the pump. The outlet side of the pump then is connectedto a pipe 2I leading upwardly to a header pipe 22 which is arrangedtransversely across the machine above the pug mill F. The type of pumpemployed for feeding delivers a constant, metered volume of binderliquid for each revolution and by suitable interconnection with thedriving means for the feed from the hopper E the relative amounts ofaggregate and binder may be selected and maintained, as set forth in ourprior application hereinbefore identified.

the material in the pug mill as will be apparent.

When a bituminous binder is used in the system as thus far described itis frequently necessary to heat the tank T in order that the bitumenwill flow freely. Particularly is this true when the weather is cool andwhen the material is thus heated it is extremely desirable to be able torecirculate the heated material through the pumps and contiguous pipingto facilitate flow therethrough. For this purpose we providerecirculation means new to be described.

A transfer pump recirculating valve 28 is located in the transfer pipeII forward of the couplings 6'I and is connected by a pipe 29 to theoutlet connection |9 leading from the tank T to the feeder pump H. Afeeder pump recirculating valve 30 is arranged in the feeder pipe 2|leading y from the pump l! and is connected by a fitting 3| to the tankT near an upper side thereof. Normally the valve 28 is arranged to openthe flow through the pipe shutting off pipe 29, and valve 30 issimilarly disposed to open the passage through pipe 2| and close off thetank connection 3|. However by moving the valve 28 to close off thecouplings 6| and open the passage between the pipes and 29 the transfer'pump It may operate to withdraw binder from the tank at the outlet l9,circulate it through the pipes 29', and i6, and back to the tank, while,by moving valve 38 to close offthe header pipe 22 and open a passagebetween the pipe 2! and tank connection 3 I, the feeder pump Il may takebinder from the tank at i9 and circulate it through pipes l3 and 23 andback into the tank. Recirculation hrough both of these pumps l4 and Hand attenda-nt connections is thus provided for whenever it may berequired.

To further facilitate proper pumping both the transfer and feeder pumpsl4 and I! are provided with jackets enclosing water circulating chambers32 and hot Water, or other heating medium, is circulated through thesechambers by pipes to thus heat the pumps. this purpose is provided byconnection of the pines 33 to the water pump, cooling system andradiator H of the internal combustion power plant or engine I used todrive the working parts of the machine.

In some types of road construction, water is used as a binder for theaggregate or base coarse material and for such work the tank T is usedto contain the water and certain parts of the piping system as thus fardescribed also play a part. The water from the relay truck or tank truckis taken through the hose 5 and pumped into the tank by the transferpump l4. A water pump 34 is arranged beneath the tank T for constantsuction and the outlet pipe 36 of the pump is run upwardly andrearwardly to a connection at 31 with the side or end portion of theheader pipe 22 opposite the aforesaid pipe 2|. A meter 38 is arrangedinthe pipe 36 to meter the water Hot water for flowing therethrough. Thesuction line 35 of to water pump 34 runs through a strainer 43 to athree-way valve 44 which makes connection With connections thus made itis apparent that,

by proper manipulation of the valves, the feed from the bitumen feederpipe 2| may be cut off and water pumped by the water pump 34 will becarried to the spray pipes 25 and from there sprayed upon the materialin the pug mill.

It sometimes is desirable to spray the road or material thereon behindthe machine and water for this purpose is provided for by connection ofa pipe 39 to the outlet pipe 36 through a shut-off valve ill. The pipe39 runs rearwardly to an end of a transversely extending perforatedspray bar 4| from which the water will be sprayed onto the road whensaid valve 40 is opened. The spray bar 4! is of course locatedrearwardly and beneath the machine as indicated in Fig. 1.

All of the pumps are provided with drive means such as sprockets 42 andmay be operated by the power unit I by suitable connections, not hereshown.

A three-way valve ll is placed at the junction of the pipes 8 and 35with the outlet l9 and when pumping oil or bituminous binder to thespray manifold this valve connects the feeder pump intak line to thetank outlet l9. On the 'other hand when pumping water to the spraymanifold this valve connects the intake line of the water pump 34 tothis outlet. When recirculating a bituminous binder through the pumpsthe valve connects the outlet is to both pipes l8 and 29.

A similar valve 48 is placed in the outlet pipe l6 of the transfer pumpI4 and normally this valve is adjusted to permit fluid flow from pump totank as has been previously described, the remaining outlet'port of thevalve being plugged as designated at 49 in Fig. 2. If it is desired todrain the tank this plug may be removed and the valve adjusted to shutoff the flow through pipe I6 to tank and direct it through the openingformed when the plug is removed. By then adjusting the valve 28 toconnect pipes H and 23 the transfer pump 54 may draw out the contents ofthe tank through the outlet l9 and discharge them to a container or pipeconnected to valve 48.

The spray bars 24 as shown in Fig. 3 particularly are provided withelbow-shaped spray nozzles 50 screwed into suitable openings 5| on uppersides of the bars and turned first upwardlyand then downwardlytherefrom. Thus the nozzles 56 are at the highest points of the sprayingsystem and when the feed of binder material to the manifold is shut ohthe spray from the spray bars will immediately cease. This featureconstitutes a distinct improvement in the spray manifold disclosed inour previous application in which the spray bars were lower than partsof the piping resulting in considerable drainage and dripping. Inasmuchas it is necessary to nicely and correctly proportion the binder to theaggregate such dripping was a hindrance as an excess of binder in a partof the mix would result each time the machine was shut down andrestarted.

It is understood that suitable modifications may be made in thestructure as disclosed, provided such modifications come within thespirit and scope of the appended claims. Having now therefore fullyillustrated and described our invention, what we claim to be new anddesire to protect by Letters Patent is:

In a machine for preparing road building materials and having a liquidstorage tank, a liquid receiving means and operative in conjunction witha liquid supply source, a liquid supply system comprising a transferpump having its inlet normally connected to the liquid supply source andits outlet connected to the tank, a feeder pump having its inletconnected to the tank and its outlet normally connected to the liquidreceiving means, means for shifting the outlet of the feeder pump fromthe receiving means to the tank for recirculating liquid through thepump, the said tank having an outlet connected to the inlet of thefeeder pump, means for connecting said tank outlet also to the inlet ofthe transfer pump for recirculating liquid through that pump, and meansfor disconnecting the transfer pump inlet from. the liquid supply sourcewhile said inlet is connected to the outlet of the tank.

EGON G. BERG.

MELVIN OVESTRUD.

